BANGKOK: A string of grenade blasts shook a northern Thai city popular with foreign tourists, leaving several people wounded in attacks that police said Saturday could be linked to the kingdom's deadly political crisis.

The explosions in Chiang Mai on Friday evening came hours after the Constitutional Court nullified a February general election disrupted by opposition protests, angering government supporters.

The targets were a seafood restaurant, a petrol station and a brewery that has faced criticism because of its controlling family's links with anti-government protesters.

Four people were wounded but were out of danger Saturday and had returned home, Chiang Mai provincial police commander Grit Gitilue said by telephone.

"We established two possible motives for the attacks - personal conflict or politics. We are giving more weight to the second one," he said, adding that no suspects had been arrested.

Two grenades were also fired near an anti-government rally in the eastern province of Chonburi on Friday evening but nobody was hurt, police said.

The unrest is a blow to efforts to lure back tourists after a state of emergency was recently lifted in Bangkok in response to an easing of months of political violence that has left 23 people dead.

The violence, mostly concentrated in Bangkok, has often targeted opposition protesters seeking to topple Prime Minister Yingluck Shinawatra's government and install an unelected "people's council" to oversee reforms.

Thailand has been bitterly divided since her elder brother Thaksin Shinawatra was ousted as premier by royalist generals in a 2006 coup.

Yingluck has been charged with negligence in connection with a rice subsidy scheme, and could face impeachment within weeks.

Her supporters, known as the "Red Shirts", have warned that they will not tolerate a "judicial coup" to oust the government through the courts.

The red-clad movement was due to hold a political rally on Saturday evening in the seaside city of Pattaya.

Their mass protests against the previous government in 2010 triggered street clashes and a military crackdown that left more than 90 people dead in the country's worst civil unrest in decades.

Yingluck's Puea Thai Party had been expected to win the February election, which was boycotted by the opposition.

The polls were annulled on the grounds that they were not held nationwide on the same day, due to the disruption by demonstrators.

Parties linked to Thaksin - who lives in Dubai to avoid prison for corruption - won every previous election for more than a decade, helped by strong support in the north.

But many southerners and Bangkok residents accuse the Shinawatra family of raiding the public coffers to buy the loyalty of rural voters through populist policies. -AFP

BRISBANE, Australia: A light aircraft used for skydiving crashed in an airfield in eastern Australia on Saturday and burst into flames, killing all five people on board, police said.

The plane veered left shortly after taking off from the Caboolture airstrip, 50 kilometres (31 miles) north of Brisbane on Australia's east coast, before plunging to the ground.

"We have a pilot and there were four skydivers on board and they were the only five people that were on board," Queensland police superintendent Michael Brady told Sky News.

Brady said a male pilot, two skydiving instructors and two skydivers including a woman were on board, but could not confirm reports that their family members were watching as the plane plummeted to the ground.

Forensic investigators were at the scene but there was no immediate word on what caused the crash, with the airport closed until further notice.

Bryan Carpenter, who works at the airfield used mostly for small aircraft, said the plane was a Cessna 206, which was often used on skydiving flights.

Rescue workers quickly reached the scene and the fire was extinguished within minutes, Queensland Fire and Rescue Service said.

Mark Thompson, who was at the scene, told reporters that dozens of people rushed to help put out the fire but the heat forced them back.

"When I got there there was nothing to be done," he said.

"There was just wreckage on the ground. It was well and truly burnt out."

In September 2010, nine people were killed in a skydiving plane crash in New Zealand when the aircraft crashed and burst into flames shortly after takeoff near the Fox Glacier tourist spot. There were no survivors. -AFP

QUETTA, Pakistan: A collision between two passenger buses and a petrol tanker killed 35 people in southwest Pakistan on Saturday, officials said, with many of the victims burning to death.

A bus travelling to Karachi collided with the tanker in the early hours of the morning in Gadani district on the coast of Baluchistan province, senior administration official Akber Haripal told AFP.

"The bus and the tanker had a head-on collision and the oil tanker turned over, but the situation got worse when a second passenger bus coming from behind rammed into the first bus as it skidded on the oil spilled on the road," he said.

The first bus then caught fire, he said, adding that 35 people were killed, most burning to death while trapped inside the bus, and 30 were injured.

Amir Sultan, another senior administration official confirmed the incident and toll and said the dead bodies were "beyond recognition".

"These passengers buses travelling between Baluchistan and Karachi have automatic hydraulic doors and their windows are sealed because the buses are air conditioned, so most of the passengers were trapped inside," he said.

Sultan said the injured were being taken to Karachi after receiving first aid at a government-run medical dispensary because there was no hospital in the area.

Pakistan has one of the world's worst records for fatal traffic accidents, blamed on poor roads, badly maintained vehicles and reckless driving. -AFP